location_guanai/QuickSearchLocation/Classes/Category/UITextField+Extension.swift

//
//  UITextField+Extension.swift
//  QuickSearchLocation
//
//  Created by mac on 2024/4/12.
//

import UIKit

extension UITextField {
    
    // MARK: 是否都是数字
    /// 是否都是数字
    /// - Returns: 返回结果
    func validateDigits() -> Bool {
        let digitsRegEx = "[0-9]*"
        let digitsTest = NSPredicate(format: "SELF MATCHES %@", digitsRegEx)
        return digitsTest.evaluate(with: self.text)
    }
    
    
    // MARK: 设置富文本的占位符
    /// 设置富文本的占位符
    /// - Parameters:
    ///   - font: 字体的大小
    ///   - color: 字体的颜色
    func setPlaceholderAttribute(font: UIFont, color: UIColor = .black) {
        let arrStr = NSMutableAttributedString(string: self.placeholder ?? "", attributes: [NSAttributedString.Key.foregroundColor: color, NSAttributedString.Key.font: font])
        self.attributedPlaceholder = arrStr
    }
}

/// 默认最大输入字数为15
var maxTextNumberDefault = 11
// MARK: 设置最大输入字数
extension UITextField {
    
        /// 以runtime的形式UITextField添加最大输入字数属性
        public var maxTextNumber: Int {
            set {
                objc_setAssociatedObject(self, &maxTextNumberDefault, newValue, objc_AssociationPolicy.OBJC_ASSOCIATION_COPY_NONATOMIC)
                self.addChangeTextTarget()
            }
            get {
                if let rs = objc_getAssociatedObject(self, &maxTextNumberDefault) as? Int {
                    return rs
                }
                return 15
            }
        }
    
        /// 添加限制最大输入字数target
        public func addChangeTextTarget(){
            self.addTarget(self, action: #selector(changeText), for: .editingChanged)
        }
    
        @objc private func changeText(){
            //判断是不是在拼音状态,拼音状态不截取文本
            if let positionRange = self.markedTextRange{
                guard self.position(from: positionRange.start, offset: 0) != nil else {
                    checkTextFieldText()
                    return
                }
            }else {
                checkTextFieldText()
            }
        }
    
        /// 检测如果输入数高于设置最大输入数则截取
        private func checkTextFieldText(){
            guard (self.text?.utf16.count)! <= maxTextNumber  else {
                guard let text = self.text else {
                    return
                }
                /// emoji的utf16.count是2，所以不能以maxTextNumber进行截取，改用text.count-1
                let sIndex = text.index(text
                    .startIndex, offsetBy: text.count-1)
                self.text = String(text[..<sIndex])
                return
            }
        }
}